Hydraulic control system



April 14, 1942.

M. PARTIOJ' HYDRAULIC CONTROL SYSTEM" Filed June 11. 1 938 'vide a system of this kind which is I said pump,

Patented Apr. 14, 1942 UNITED sTATEs PATENT orme;

Application June 11, 193

6 Claims.

The present invention relates to hydraulic control systems of the kind including a pump always driven in the same direction and provided with means for varying its flow independently of the speed at which it is driven. 4

One object of the present invention is to probetter adapted to meet the requirements of practice and in'particular which is reversible, either automatically or at will.

Another object of the invention is to provide a system of this type adapted to control the clutch of an automobile vehicle.

With these and other objects in view, one feature of my invention consists in fitting a pump of the type pable of reversing the direction of fiowthrough for varying the rate of said flow in response to variations of the difierence between the pressures of the liquid entering the pump and the liquid leaving it, said means, movable between two extreme positions, being yieldingly applied in one of these positions bymanually adjustable means. v

Another feature of the invention, relative to the control of the clutch of an automobile vehicle, consists in connecting with said 'clutcha part operative by the liquid pressure supplied by the pump so that said clutch is let in when the liquid flows in one direction through said pump and is disengaged when the liquid flows in the opposite direction-therethrough. 1 According to still another feature of the invention, relating to the last mentioned case, means operative by, the suction of the vehicle engine are provided for acting on said pump, when the speed of the engine drops below a given value, in such manner as to tend to reverse the working of the pump so as to obtain the disengagement of the clutch.

Other features of the present invention will result from the following some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafter described, with reference to the accompanying drawing, given merely by way of example, and in which:

Fig. 1 is a diagrammatic vertical view of a hydraulic control system according to the present invention. I

Fig. 2 is a' vertical sectional view illustrating, by way of example, the structure of a pump used in connection with the system of Fig. 1;

'Fig. 3 is a diagrammatic vertical sectional view of the system according to the invention in comf above referred to with means, ca-

8, Serial No. 213,283

detailed description of I V at both ends.

drawing, that is to bination with an internal combustion engine and a clutch associated with said engine.

The pump shown by way of example by Fig. 2 includes a casing l and a rotor 2 .rotated therein through any suitable driving on the drawing. This casing is provided with chambers or passages 3 and 4, located respectively on opposite sides ofthe rotor. The surface of the rotor is adapted to slide with afiuid-tight fit against the inner wall of the stator between A piston 5 is adapted to recipto the rotor'under themthese chambers. rocate with respect fluence of a block groove of the piston, said block 6 being kept in fixed position with respect to the pump. bodyor casing l by means of a pin 1. v

Chamber 3 communicates through a pipe 10 with any container, for instance a tank A. On the other hand, through a pipe .II with a tank B (Fig. l)

Pin 1 is carried by.-a lever l2, pivoted at1l3 to the pump body. The movement ofsaid lever 12 about its pivot I3 is limitedby the provision of abutments M and 115, also. carriedby the pumpbody. i

The lower end of lever 12 is pivoted to a member l6, inserted between two springs l1 and 1 l8 the outer ends of which. are fixed to the ends of a support l9, slidable along a rod 20,.carried by a frame 2|. The position of support l9. along rod is controlled by meansof a crank keyed on a threaded rod 24 journalled i'n. frame 2 I and screwing in l a threaded housingprovided in support l9.

Frame 2| is provlded with a graduatedscale cylinder 26 tends to produce'an angular 'dis-' I placement of lever 12 about its pivot l3. 7

As shown by the drawing, cylinder 26 is closed a pipe 30 with chamber 4 and the other end communicates through a pipe 3| with chamber 3.

The system above described operates in the following manner;

- When pin 1 is in the positionshown in the say in eccentric relationfto means, not visible slidable transversely. ina chamber 4' communicates One end communicates through manner as abovedescribed.

through a pipe I with a a piston 42 is movable.

the axis of the pump body on the left hand side thereof,,and supposing that the pump rotor is turning caused, under the influence of block 6 cooperating with pin I, to reciprocate within said rotor, and liquid passes from chamber 3 into chamber 4, that is to say is fed from tank A to tank B.

The position of lever eccentricity of pin 7, is controlled by means of crank 25, acting through stituted bysprings I 1 and I8.

If, for some reason, the pressure in chamber 4 is transmitted through pipe 3i! to the part flof cylinder 26 on the against the elastic resistance of spring I8, This in the clockwise direction, piston is' the resilient means cona predetermined value, as this pressure leftof piston 21,'this piston is" moved toward the right, displacing. lever I2 I2, which determines the compartment of which is connected through a pipe 38 withthe suction of the vehicle engine.

I The rod 28 of piston 21 carries a finger 32 fixed at right angles thereto and adapted to cooperate with a finger 33 similarly carried by rod 29.

The system' above described Works in the following manner:

Supposing the parts to be in the relative positions shown by the drawing, the rotor of the pump turning in a clockwise direction causes liquid to flow from chamber 3- to chamber 4, thus moving piston 42 toward the left and acting.

through rod 45 and lever 44, to apply the coop- .erating. parts of the clutch against one another.

" Once this result 1 keeps increasing has been obtained, the pressure in the chamber 4 of the pump.

7 pressure is transmitted through pipe 3| to reduces the eccentricity of pin 'I'and consequently relieves the pressure in chamber I Supposing now that, by acting upon crank 1everJ2 is turned into theoppositeposition; that 'istosay that its end I6 is I side ofa vertical line passing through pivot I3,

4. Should this pressure still remain too high, the action of pisthe rotor,2 st ill turning in the same, direction as above, that is to say in the clockwise direction,

- and for instance at the same speed. It .will be readily u derstoodthat the working of the pump is reversed; so that the liquid flows from chamber Once the lever is: applied against one of its abutments, I4 or I5, it is possible, by turning jcrank 25 to compress more or less thespring, I!

through which the lever is applied against forflessxcompressed, the relief device 26 21 is more or 'less sensitive to an increase of the dis- 7 charge pressure.

20f co rse, although I have disclosed a specific type of pump y way ofexample, it is clear that the system according to. the invention applies to l depends'u-pon the relative position of a-member such as pin lot the above j characters designating the same parts.

{In this case, chamber 3- communicates through 'a' pipe II with a tank-T.

0n the other hand, chamber 4 communicates cylinder 43 inside which is pivoted to a lever 44 the engine.

.A rod 29 is pivoted at one end to lever I2 and it has its opposite end fixed to a membrane 31 forming a partition in a box the left hand I2, from the position especially rotary pumps, the

The rod 45 of this piston adapted to control the clutch 4| inserted between the gear .box'40 and the right hand end of cylinder 26 and it pushes piston 21 toward the left. Through cooperating fingers 32 and 33, this movement is transmitted to rod 29, which causes lever I2 to turn toward the left, thus reducing the flow through the pump and finally bringing'pin 1 at or near its concentric position, where it merely keeps the piston 42 applied toward the left, without increasing the pressure in chamber 4. r r

If lever I2 is turned toward the left beyond its vertical position so that pin 1 is nowon the left hand side'of theaxis of the pump body, the working of the pump is reversed, liquid flowing from chamber 4 to chamber 3, and through piston 42, rod 45 and lever 44, the clutch is disenaged. I a I When the speed of the engine drops, the suction in manifold 39 increases. This suction'is transmitted through pipe 38 to chamber 35;and the movable partition 31in said chamber is drawn "toward the left, thus actuating rod 29-also toward the left. As normally lever I2 is in, or close to,

its vertical'position, this movement of rod 29 (re-- sulting from a drop of the enginespeed) is sulficient to "move said lever toward the left beyond said vertical position, thus of the pump to be reversed, disengagement of the clutch. v 1

Therefore, with my device, a drop of the speed of revolution of the engine automatically produces the disengagement of the clutch, and the driver can change the gear combination without having toboth'er about' the operation of the clutch. f I

As soon as the engine again turns more .39 decreases, rod 29 is the right and'springs I1 and I8 bring back lever l2 into its original position. A Y Y I I In a general manner, while I have, inthe above description, discl'osed'what I deem to be practical and eflicient embodiments of the present invention,it should be well understood that I do not wishto be-limited thereto as there might be hended withinth e' scope of the accompanying claims. e

What I claim isi 1. A hydraulic control system which comprises,

in combination, two passages for a liquid, a liquid said flow within two given limits corresponding respectively to these extreme positions and consequently to opposed directions of said flow through the pump, manually adjustable means for yieldingly applying said movable means in at least one of said two extreme positions, and distinct means operative by the difierence, either in one direction or the other, between the respective liquid pressures in said passages, for automatically controlling the position of said movable means.

2. A hydraulic control system which comprises, in combination, two liquid passages, a pump body inserted in series between said passages, a part rotatable with respect to said body always in the same direction, a member movably positioned with respect to said body, mechanical means, connected to said member and operative by said part, for causing liquid to flow through said pump body and said passages, either in one direction or in the other and at a variable rate according to the position of said member with respect to said body, two abutments for said member for limiting the movement thereof with respect to said body to two extreme positions corresponding respectively to opposed directions of flow of the liquid through said pump, manually adjustable means for yieldingly applying said member against at least one of said two abutments, and distinct means operative by the difference, either in one direction or the other, between the respective liquid pressures in said passages, for automatically controlling the position of said member. a

3. A hydraulic control system which comprises, in combination, two passages for a liquid, a cylindrical pump body inserted in series between said passages, a rotor in said body adapted to be driven always in the same direction, a member movable with respect to said body transversely thereto, mechanical means, connected to said member and operative by said rotor, for causing liquid to flow through said pump body and said passages, either in one direction or in the other and at a variable rate according to the position of said member with respect to said body, two abutments for said member for limiting the displacement thereof with respect to said body to two extreme positions, corresponding respectively to opposed directions of flow of the liquid through said pump, manually adjustable spring means for yieldingly applyingsaid member against at least one of said two abutments, a cylinder mounted in fixed position with respect to said body, a piston in said cylinder having its faces subjected to the respective liquid pressures in said passages, and means operative by said piston for controlling the position of said member with respect to said pump body.

4. A hydraulic control system comprising a conduit, a pump interposed in said conduit driven at all times in one direction, reversing means associated with said pump for reversing the pumping action thereof, controlling means for said reversing means, means for manually adjusting said controlling means and means responsive to the pressure difference at the inlet and outlet of said pump modifying the action of said controlling means.

5. A hydraulic control system comprising a conduit, a pump interposed in said conduit driven at all times in one direction, reversing means associated with said pump for reversing the pumping action thereof, controlling means for said reversing means, means for manually adjusting said controlling means and means responsive to the pressure difference at the inlet and outlet of said'pump controlling the action of said controlling means.

6. A hydraulic control system comprising a conduit, a pump interposed in said conduit driven at all times in one direction, reversing means associated with said pump for reversing the pumping action thereof, controlling means for said reversing means, means for manually adjusting said controlling means and pressure responsive means controlling said controlling means.

MAURICE PARTIOT. 

